US20010026565A1 - Wavelength multiplexing system, wavelength adjusting system, and optical transmitter - Google Patents

Wavelength multiplexing system, wavelength adjusting system, and optical transmitter Download PDF

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Publication number
US20010026565A1
US20010026565A1 US09/813,573 US81357301A US2001026565A1 US 20010026565 A1 US20010026565 A1 US 20010026565A1 US 81357301 A US81357301 A US 81357301A US 2001026565 A1 US2001026565 A1 US 2001026565A1
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Prior art keywords
wavelength
optical
semiconductor laser
signal
driving circuit
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US09/813,573
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English (en)
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Hitoshi Takeshita
Naoya Henmi
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NEC Corp
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NEC Corp
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Publication of US20010026565A1 publication Critical patent/US20010026565A1/en
Abandoned legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/501—Structural aspects
    • H04B10/503—Laser transmitters
    • H04B10/504—Laser transmitters using direct modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/508—Pulse generation, e.g. generation of solitons
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/572—Wavelength control

Definitions

  • the present invention relates to a wavelength multiplexing system and a wavelength multiplexing apparatus in a wavelength multiplexing and optical network, and in particular, relates to a wavelength multiplexing system which obtains a plurality of signal carrier wavelengths by filtering optical output from a multiple mode oscillating semiconductor laser using an optical filter, and a wavelength adjusting method and apparatus which adjust output signal carrier wavelengths by changing the center of the wavelengths output from the optical filter.
  • the wavelength multiplexing system is comprised of a plurality of semiconductor lasers which emit single mode light beams having different wavelengths for generating a plurality of wavelength multiplexed optical signals by an optical coupler for coupling a plurality of oscillating light beams or a wavelength router through a semiconductor laser provided with a modulating function for directly modulating the oscillating light beams emitted from the plurality of semiconductor lasers or through the modulator which modulates quantity of light.
  • semiconductor lasers which emit single mode light include DFB (Distributed Feedback laser) and DBR (Distributed Bragg Reflector laser).
  • a semiconductor laser light source which is formed by integrating a light modulator and a DFB laser on a single substrate.
  • light modulators There are two types of light modulators; one is the modulator utilizing an EA (Electro-Absorption) effect, in which the amount of absorbed light changes depending on the applied electric field to the p-n junction of the semiconductor, and another one is the modulator using Mach-Zehnder interferometer.
  • EA Electro-Absorption
  • the wavelength adjustable optical transmitter is generally provided by changing the oscillating mode wavelength by accurately controlling an injection current into an wavelength adjusting semiconductor laser or by controlling the light switch after multiplexing a plurality of fixed multiple wavelengths emitted as outputs of the single mode oscillating laser through the light switch.
  • Japanese Unexamined Patent Application, First Publication No. Hei 9-260790 discloses a technique to stabilize the output light wavelength and the output light intensity.
  • the first problem is that the manufacturing cost increases in proportion to the increase of the number of the multiplexing wavelengths.
  • the reason for this problem is that the system requires a number of semiconductor lasers and temperature control circuits equal to that the multiplexing wavelengths.
  • the second problem is the high driving cost. Since the temperature of the individual semiconductor laser needs to be controlled, power consumption of the control circuit becomes high.
  • the third problem is that high manufacturing cost of the wavelength adjusting optical transmitter, because this transmitter needs to use expensive wavelength adjusting semiconductor lasers or a plurality of single mode oscillating semiconductor lasers having a fixed oscillating wavelength.
  • the present invention is made to solve the above-described problems and the object of the present invention is to provide a wavelength multiplexing optical transmitter and a wavelength adjusting optical transmitter at a reduced cost and at a reduced size.
  • Another object is to provide is to provide a optical transmitter capable of transmitting a large volume of information by adopting the wavelength multiplexing technique at a reduced cost.
  • the object of this light transmitting system is to generate a plurality of channels by slicing the emission spectrum of a multi-mode laser using a light filter, and to realize direct current modulation of the semiconductor laser.
  • the first aspect of the present invention provides a wavelength multiplexing method for use in an optical network that adopts a wavelength multiplexing system comprising the steps of driving a semiconductor laser by direct current modulation in response to an input electric signal, and obtaining at least one signal carrier wavelength by dividing output wavelengths of the multi-mode oscillation semiconductor laser using an optical filter which passes at least one wavelength in said output wavelengths of said semiconductor laser.
  • the second aspect of the present invention provides a wavelength multiplexing optical transmitter comprising a multi-mode oscillation semiconductor laser, a laser driving circuit for driving said semiconductor laser by an input electric signal, and an optical filter having at least one passing band in an optical output from said multi-mode oscillation semiconductor laser; wherein at least one or more than one signal carrier wavelength is obtained by filtering the output of said semiconductor laser for slicing the output wavelength region of said semiconductor laser.
  • the third aspect of the present invention provides a wavelength adjusting apparatus using the above-described wavelength multiplexing optical transmitter in which the signal carrier wavelength is changed by changing the transmitting wavelength region of said optical filter.
  • said wavelength adjusting apparatus further comprises a laser driving circuit that directly modulates the multi-mode oscillation semiconductor by an electric current and the driving circuit that converts the electric signal introduced in the driving circuit into optical signals having more than one signal carrier wavelengths, and said driving circuit changes said signal carrier wavelength by changing the transmitting wavelength region of said optical filter.
  • the first effect of the present invention is that multi-casting of the signals can be facilitated, since one semiconductor laser can generate a plurality of different signal carrier wavelengths and since one wavelength multiplexing optical transmitter can output a plurality of different signal carrier light beams.
  • the second effect of the present invention is that the present wavelength multiplexing optical transmitter can be produced at a low cost since the multi-mode oscillation semiconductor laser can be produced at a lower cost than that of the conventional single mode oscillation semiconductor laser.
  • the third effect of the present invention is that it is possible to provide an optical transmitter, which can be operated in a stabilized bandwidth at a low power consumption and thus at a reduced cost, since the signal carrier wavelength can be determined by the optical filter, which is a passive component, in contrast to the conventional wavelength multiplexing optical transmitter using a single mode oscillating semiconductor laser, since the signal carrier wavelength of the conventional optical transmitter is determined by the oscillating wavelength of the semiconductor laser.
  • the fourth effect of the present invention is that the present optical transmitter is stable in fluctuating environment because the signal carrier wavelength of the present optical transmitter is determined by the optical filter, which is a passive component, in contrast to the conventional wavelength multiplexing optical transmitter using a single mode oscillating semiconductor laser, since the signal carrier wavelength of the conventional optical transmitter is determined by the oscillating wavelength of the semiconductor laser.
  • the fifth effect of the present invention is that a wavelength adjusting optical transmitter can be provided at a low cost because a desired oscillating mode can be obtained by switching the output modes of the multi-mode oscillation semiconductor laser using an optical filter.
  • FIG. 1 is a block diagram showing the structure of the wavelength multiplexing optical transmitter of the present invention.
  • FIG. 2 is a diagram explaining respective blocks of the wavelength multiplexing optical transmitter of the present invention.
  • FIG. 3 is a block diagram showing the wavelength multiplexing optical transmitter according to the first embodiment of the present invention.
  • FIG. 4 is a block diagram showing the structure of the wavelength multiplexing optical transmitter according to the second embodiment of the present invention.
  • FIG. 5 is a block diagram showing the structure of wavelength multiplexing optical transmitter of the present invention.
  • FIG. 6 is a block diagram showing the structure of wavelength multiplexing optical transmitter of the present invention.
  • FIG. 7 is a block diagram showing the structure of wavelength multiplexing optical transmitter of the present invention.
  • FIG. 8 is a block diagram showing the structure of wavelength multiplexing optical transmitter of the present invention.
  • FIG. 9 is a block diagram showing the structure of wavelength multiplexing optical transmitter of the present invention.
  • FIG. 10 is a block diagram showing the structure of wavelength multiplexing optical transmitter of the present invention.
  • a wavelength multiplexing optical transmitter 100 comprises a multiple mode oscillation laser 101 , a laser driving circuit 102 for driving the multi-mode oscillation laser 101 , and a light filter for filtering the light that is output from the multiple mode oscillation laser 101 .
  • the multiple mode oscillation laser 101 is a Fabry-Perot laser.
  • ⁇ represents a oscillating wavelength
  • L a length of the resonator
  • n is a effective refractive index
  • This modulation system obtaining the modulated wavelengths of multiple wavelengths by a single modulating wave is quite effective in the case of a broad casting mode to the general public or in the case of a multi-cast mode communication to a plurality of particular people.
  • n wavelength multiplexing communication is capable of exchanging information, which is n times larger than that of the single wavelength communication.
  • An example of an individual device which transmits a plurality of wavelength bands is a waveguide type diffraction grating (AWG: Arrayed Waveguide Grating). It is also possible to form an optical filter capable of transmitting a plurality of bands by combining a plurality of optical filters which transmit a single transmitting region.
  • the transmitting bandwidth is not always required to be variable and a device having a fixed transmitting bandwidth can be used.
  • the transmitting bandwidth When it is necessary to change the transmitting bandwidth, it is possible to provide a device having a variable transmission bandwidth by the addition of a Peltier element to, for example, an optical band pass filter made of SiO 2 type material (such as the above-described AWG) and by controlling the temperature of the filter. Furthermore, in the case of an optical filter using an etalon, the transmitting wavelength region can be changed by addition of mechanisms such as a stepping motor or a piezoelectric element.
  • a Peltier element to, for example, an optical band pass filter made of SiO 2 type material (such as the above-described AWG) and by controlling the temperature of the filter.
  • the transmitting wavelength region can be changed by addition of mechanisms such as a stepping motor or a piezoelectric element.
  • an electric signal in a desired form is input into a wavelength multiplexing optical transmitter 100 .
  • the signal is subjected to direct current modulation, after the signal is introduced into the laser driving circuit 102 in the wavelength multiplexing optical transmitter 100 .
  • the multi-mode oscillation semiconductor laser 101 outputs an optical signal following the input current input from the laser driving circuit 102 .
  • wavelength multiplexing optical signals determined by the pass wavelength characteristics of the wavelength filter 103 , are output from the wavelength multiplexing optical transmitter 100 by filtering the output light beams of the multi-mode oscillation semiconductor laser 101 using an optical filter 103 at the wavelength range thereof.
  • a wavelength multiplexing transmitter 300 comprises a multi-mode oscillation semiconductor laser 301 that emits light beams in a wavelength range around 1550 nm, a laser diode driving circuit 302 for driving this multi-mode oscillation laser 301 , and a band pass optical filter 303 having a pass band width of 5 nm for filtering the optical output from the multi-mode oscillation semiconductor laser 301 .
  • an electric signal in a desired code form is input into the wavelength multiplexing optical transmitter 300 .
  • this electric signal After being introduced into the laser driving circuit 302 in the wavelength multiplexing optical transmitter 300 , this electric signal performs direct current modulation of the multi-mode oscillation semiconductor laser 301 .
  • the multi-mode oscillation semiconductor laser 301 outputs the optical laser signals in response to the input current from the laser driving circuit 302 .
  • This modulation system can modulate the output light by directly modulating the current injected into the semiconductor laser 301 .
  • the semiconductor laser If the current higher than that of the oscillation threshold of the semiconductor laser is injected, the semiconductor laser emits light, which is represented as the state in which a signal bit is at [1], and, when the current lower than the oscillation threshold of the semiconductor laser is injected, the semiconductor laser does not emit light, which is represented as the state in which the signal bit is at [0].
  • Demodulation is executed by providing a demodulator at a reception side or by providing an RZ demodulator.
  • a modulator for the error correction is provided. For example, when Reed Solomon coding is conducted at the sending side, a Reed Solomon decoder at the reception side carries out decoding.
  • an optical signal is output whose signal carrier wavelength has a 3 dB attenuation band width of 5 nm due to filtering the output light of the multi-mode oscillation semiconductor laser 301 using a band pass filter 303 having only one band pass characteristic for passing a 3 dB attenuation band in a width of 5 nm.
  • This embodiment is useful for communication by the broadcast mode.
  • an electrical signal in a desired NRZ (Non-Retum Zero) code is first input into the wavelength multiplexing optical transmitter 400 .
  • this electrical signal in the NRZ code After being introduced into the laser driving circuit 402 in the wavelength multiplexing optical transmitter 400 , this electrical signal in the NRZ code performs direct current modulation of the multi-mode oscillation semiconductor laser 401 .
  • the multi-mode oscillation semiconductor laser 401 outputs the optical signal in response to the current input the laser driving circuit 402 .
  • FIG. 4 an electrical signal in a desired NRZ (Non-Retum Zero) code
  • two optical output signals having two different signal carrier wavelengths and having a 3 dB attenuation band width of 5 nm are obtained by filtering the output light of the multi-mode oscillation semiconductor laser 401 using a band pass filter 403 having two different band pass characteristics for passing two of each 3 dB attenuation band in width of 5 nm.
  • This NRZ code is used in the SDH transmission network, and although this NRZ code is not capable of correcting errors, this is effective in communication when two signals are communicated in synchronism with each other.
  • the oscillation wavelength of the multi-mode oscillation semiconductor laser 401 is not limited to the 1550 nm, but the oscillation wavelength laser may be in the 1300 nm band.
  • the 3 dB attenuation band width of the band pass optical filter 403 is not limited to 5 nm and any band widths such as 1 nm or 10 nm can be selected.
  • an electric signal in a desired RZ (Return-Zero) code is input into a wavelength multiplexing optical transmitter 500 .
  • the electric signal in the RZ code is, after being introduced into the laser driving circuit 502 in the wavelength multiplexing optical transmitter 500 , performs a direct current modulation of the multi-mode oscillation semiconductor laser 501 .
  • the multi-mode oscillation semiconductor laser 401 outputs optical signals in response to the current input from the laser driving circuit 502 .
  • two optical output signals having two different signal carrier wavelengths and having a 3 dB attenuation band width of 5 nm are obtained by filtering the output light of the multi-mode oscillation semiconductor laser 401 using a band pass filter 403 having two different band pass characteristics for passing two of each 3 dB attenuation band in the width of 5 nm.
  • this RZ code is that used for the signal transmission, similar to the NRZ code, since the frequency band required for RZ is two times wider than that required for NRZ coding, the RZ code is not used for the SDH transmission network. However, in the RZ coding system, because the RZ code is capable of yielding better transmission characteristics than the NRZ code, an application of the RZ code may be increased.
  • the oscillating wavelength of the multi-mode oscillation semiconductor laser 501 is not limited to 1550 nm, but the wavelength may be, for example, in a 1300 nm band.
  • the 3 dB attenuation band width is not limited to 5 nm, but any width can be selected such as 1 nm or 10 nm.
  • the number of the passing wavelength bands of the band pass filter 503 is not limited to two, and it is possible to use an optical band pass filter having 16 passing wavelength bands can be used.
  • the wavelength multiplexing optical transmitter 500 outputs an optical output, in which 16 different signal carrier light beams are multiplexed.
  • an electric signal in a desired code form is input in a wavelength multiplexing optical transmitter 600 .
  • This electric signal may be in the NRZ code, RZ code, or any other code forms.
  • This electric signal is, after being coded into the Reed Solomon code by an error correction coding device 604 in the wavelength multiplexing optical transmitter 600 .
  • the thus coded electric signal performs a direct current modulation.
  • the multi-mode oscillation semiconductor laser 601 outputs optical signals in response to the current input from the error correction coding device 604 .
  • the coding operation executed in the error correction coding device 604 is not only the above-described coding into the Reed Solomon code, which is called one type of multidimensional cyclic coding, but also includes coding into the error correction codes such as BCH code or Hamming code.
  • two optical output signals having two different signal carrier wavelengths and having a 3 dB attenuation band width of 5 nm are obtained by filtering the output light of the multi-mode oscillation semiconductor laser 401 using a band pass filter 403 having two different band pass characteristics for passing each of two 3 dB attenuation band in the width of 5 nm.
  • the oscillating wavelength of the multi-mode oscillation semiconductor laser 601 is not limited to 1550 nm, but the wavelength may be, for example, in a 1300 nm band.
  • the 3 dB attenuation band width is not limited to 5 nm, but any width can be selected, such as 1 nm or 10 nm.
  • the number of the passing wavelength bands of the band pass filter 603 is not limited to two, and an optical band pass filter having 16 passing wavelength bands can be used.
  • the wavelength multiplexing optical transmitter 600 outputs an optical output, in which 16 different signal carrier light beams are multiplexed.
  • an electric signal in a desired form is input into the wavelength adjusting optical transmitter 700 .
  • this electric signal in the NRZ code form performs the direct current modulation.
  • the multi-mode oscillation semiconductor laser 701 outputs an optical output in response to the current input from the laser driving circuit 702 .
  • two optical output signals having two different signal carrier wavelengths and having a 3 dB attenuation band width of 5 nm are obtained by filtering the output light of the multi-mode oscillation semiconductor laser 701 using a band pass filter 703 having two different band pass characteristics for passing each of two 3 dB attenuation band in the width of 5 nm.
  • the center wavelength passing the optical band pass filter 703 can be changed and also can be set by applying a predetermined voltage to the wavelength control device 710 .
  • the control of the center wavelength is not limited to the above control method, and the center wavelength passing the optical band pass filter can be changed by changing the temperature of the optical band pass filter 703 .
  • the oscillating wavelength of the multi-mode oscillation laser 701 is not limited to 1550 nm, but a 1300 nm band can be used.
  • the 3 dB attenuation band width is not limited to 5 nm, but 1 nm or 10 nm can be used.
  • an electric signal in a desired RZ code form is input into the wavelength adjusting optical transmitter 800 .
  • the electric signal in the RZ code form After being introduced into the laser driving circuit 802 in the wavelength adjusting optical transmitter 800 , the electric signal in the RZ code form performs direct current modulation.
  • the multi-mode oscillation semiconductor laser 801 output an optical output in response to the current input from the laser driving circuit 802 .
  • two optical output signals having two different signal carrier wavelengths and having a 3 dB attenuation band width of 5 nm are obtained by filtering the output light of the multi-mode oscillation semiconductor laser 801 using a band pass filter 803 having two different band pass characteristics for passing each of two 3 dB attenuation band in the width of 5 nm.
  • the center wavelength passing the optical band pass filter 803 can be changed and also can be set by applying a predetermined voltage to the wavelength control device 810 .
  • the control of the center wavelength is not limited to the above control method, and the center wavelength passing the optical band pass filter can be changed by changing the temperature of the optical band pass filter 803 .
  • the oscillating wavelength of the multi-mode oscillation semiconductor laser 801 is not limited to 1550 nm, but the wavelength may be, for example, in a 1300 nm band.
  • the 3 dB attenuation band width is not limited to 5 nm, but any width can be selected such as 1 nm or 10 nm.
  • the number of the passing wavelength bands of the band pass filter 803 is not limited to two, and it is possible to use an optical band pass filter having 16 passing wavelength bands. When using a band pass filter that passes 16 different passing wavelength band characteristics, the wavelength multiplexing optical transmitter 800 outputs an optical output, in which 16 different signal carrier light beams are multiplexed.
  • an electric signal in a desired RZ code form is input into the wavelength adjusting optical transmitter 900 .
  • the electric signal in the RZ code form After being introduced into the laser driving circuit 902 in the wavelength adjusting optical transmitter 800 , the electric signal in the RZ code form performs the direct current modulation.
  • the multi-mode oscillation semiconductor laser 901 output an optical output in response to the current input from the laser driving circuit 902 .
  • optical output signals having four different signal carrier wavelengths and each having a 3 dB attenuation band width of 5 nm are obtained by filtering the output light of the multi-mode oscillation semiconductor laser 801 using a band pass filters 903 and 904 each having two different band pass characteristics for passing two of each 3 dB attenuation band in the width of 5 nm.
  • the center wavelengths passing the optical band pass filters 903 and 904 can be changed and also can be set by applying a predetermined voltage to the wavelength control devices 910 and 911 .
  • the control of the center wavelength is not limited to the above control method, and the center wavelength passing the optical band pass filters can be changed by changing the temperature of the optical band pass filters 903 and 904 .
  • the oscillating wavelength of the multi-mode oscillation semiconductor laser 901 is not limited to 1550 nm, but the wavelength may be, for example, in a 1300 nm band.
  • the 3 dB attenuation band width is not limited to 5 nm, but any width can be selected, such as 1 nm or 10 nm.
  • the number of the passing wavelength bands of each band pass filters 903 and 904 is not limited to two, and an optical band pass filter having 16 passing wavelength bands can be used.
  • the wavelength multiplexing optical transmitter 900 outputs an optical output, in which 32 different signal carrier light beams are multiplexed.
  • band pass filters are provided as shown in FIG. 9, but the number of band pass filters are not limited.
  • a electric signal in a desired code form is input in a wavelength multiplexing optical transmitter 1000 .
  • This electric signal may be in any code forms such as the NRZ code, the RZ code, or other code.
  • this electric signal is introduced into the laser driving circuit 1002 .
  • a direct current modulation of the multi-mode oscillation semiconductor laser 1001 is carried out by the thus coded electric signal.
  • the multi-mode oscillation semiconductor laser 1001 outputs optical signals in response to the current input from the error correction coding device 1004 .
  • the coding operation executed in the error correction coding device 1004 is not only the above-described coding into the Reed Solomon code, but also includes coding into the error correction codes such as BCH code or another code.
  • two optical output signals having two different signal carrier wavelengths and having a 3 dB attenuation band width of 5 nm are obtained by filtering the output light of the multi-mode oscillation semiconductor laser 1001 using a band pass filter 1003 having two different band pass characteristics for passing two of each 3 dB attenuation band in the width of 5 nm.
  • the wavelength control device 1010 controls the center wavelength passing the optical band pass filter 1003 .
  • the control of the center wavelength is not limited to the above control method, and the center wavelength passing the optical band pass filter can be changed by changing the temperature of the optical band pass filter 1003 .
  • the oscillating wavelength of the multi-mode oscillation semiconductor laser 1001 is not limited to 1550 nm, but the wavelength may be, for example, in the 1300 nm band.
  • the 3 dB attenuation band width of the band pass optical filter 1003 is not limited to 5 nm, but any width can be selected, such as 1 nm or 10 nm.
  • the number of the passing wavelength bands of the band pass filter 1003 is not limited to two, and an optical band pass filter having 16 passing wavelength bands can be used.
  • the wavelength multiplexing optical transmitter 1000 outputs an optical output, in which 16 different signal carrier light beams are multiplexed.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Optical Communication System (AREA)
  • Semiconductor Lasers (AREA)
US09/813,573 2000-03-30 2001-03-21 Wavelength multiplexing system, wavelength adjusting system, and optical transmitter Abandoned US20010026565A1 (en)

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JP2000-095047 2000-03-30
JP2000095047A JP2001284705A (ja) 2000-03-30 2000-03-30 波長多重方式と波長可変方式及び光送信機

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EP (1) EP1146680A3 (fr)
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CA (1) CA2341983A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040184805A1 (en) * 2003-03-05 2004-09-23 Dong-Jae Shin Method for maintaining mode-locked state of fabry-perot laser irrespective of temperature change and WDM light source using the same method
US20060051103A1 (en) * 2004-09-08 2006-03-09 Ranganath Tirumala R Multi-channel fabry-perot laser transmitters and methods of generating multiple modulated optical signals
US20080131141A1 (en) * 2006-11-30 2008-06-05 Ranganath Tirumala R Parallel channel optical communication using modulator array and shared laser
US20140050238A1 (en) * 2007-11-30 2014-02-20 Megaopto Co., Ltd. Pulse light source

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005531169A (ja) 2002-05-10 2005-10-13 シーメンス　アクチエンゲゼルシヤフト 光学的偏光多重化信号の信号劣化を低減するための方法及び装置
JP4756379B2 (ja) 2004-07-15 2011-08-24 日本電気株式会社 外部共振器型波長可変レーザ
JP2007309840A (ja) * 2006-05-19 2007-11-29 Olympus Corp 光源装置及び分析装置
JP6440138B2 (ja) * 2014-02-28 2018-12-19 国立大学法人京都大学 レーザ装置

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09260790A (ja) * 1996-03-19 1997-10-03 Canon Inc 多モード発振する半導体レーザを含む光源装置

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040184805A1 (en) * 2003-03-05 2004-09-23 Dong-Jae Shin Method for maintaining mode-locked state of fabry-perot laser irrespective of temperature change and WDM light source using the same method
US7123633B2 (en) * 2003-03-05 2006-10-17 Samsung Electronics Co., Ltd. Method for maintaining mode-locked state of fabry-perot laser irrespective of temperature change and WDM light source using the same method
US20060051103A1 (en) * 2004-09-08 2006-03-09 Ranganath Tirumala R Multi-channel fabry-perot laser transmitters and methods of generating multiple modulated optical signals
US7747174B2 (en) * 2004-09-08 2010-06-29 Avago Technologies Fiber Ip (Singapore) Pte. Ltd. Multi-channel fabry-perot laser transmitters and methods of generating multiple modulated optical signals
US20080131141A1 (en) * 2006-11-30 2008-06-05 Ranganath Tirumala R Parallel channel optical communication using modulator array and shared laser
US7734189B2 (en) 2006-11-30 2010-06-08 Avago Technologies Fiber Ip (Singapore) Pte. Ltd. Parallel channel optical communication using modulator array and shared laser
US20140050238A1 (en) * 2007-11-30 2014-02-20 Megaopto Co., Ltd. Pulse light source
US8891565B2 (en) * 2007-11-30 2014-11-18 Megaopto Co., Ltd. Pulse light source

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CA2341983A1 (fr) 2001-09-30
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JP2001284705A (ja) 2001-10-12

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